1. Field of Invention
Exemplary aspects of the present invention relate to an image forming apparatus, and more particularly to an image forming apparatus capable of providing a stable belt movement in a belt unit.
2. Description of the Related Art
A related art image forming apparatus with a detachable belt unit has been known to form a toner image (e.g., a monochrome image or a color image) on a transfer sheet. The detachable belt unit includes, for example, an detachable intermediate transfer unit and a detachable sheet conveyance unit. The intermediate transfer unit includes an intermediate transfer belt on which the toner image is transferred before being transferred onto a transfer sheet, and the sheet conveyance unit includes a sheet conveyance belt by which the transfer sheet is conveyed in a process of forming the toner image on the transfer sheet.
One example of the related art image forming apparatus employs the detachable intermediate transfer unit including the intermediate transfer belt and a support member that supports the intermediate transfer belt to provide a quality image. Another example employs the sheet conveyance belt that has a high stability to meet a demand for a higher conveyance speed of the transfer sheet resulting from an increased output speed of the image forming process. Still another example employs the intermediate transfer belt unit and sheet conveyance belt unit to form a full color image by superimposing one color image on another with a tandem system of a plurality of image forming mechanisms. This tandem system can provide a full color image at a speed as fast as forming of a monochrome image.
These belts such as the intermediate transfer belt and sheet conveyance belt included in the detachable belt units, generally deteriorate over time. Accordingly, each belt should be replaced after a certain amount thereof is consumed. The intermediate transfer belt, for example, should be replaced so that an occurrence of deteriorating the image quality caused by the deterioration of the intermediate transfer belt may be reduced.
The detachable belt unit in the relate art image forming apparatus applies a rigid frame, for example, a sheet metal for front and rear plates, and an extruded aluminum for a stay. Thereby, the belts may be replaced by a skilled user and/or a service personnel having expertise in the replacement.